Piedmont Mechanical Specializes in HVAC, piping, sheet metal, and machinery installation. http://www.piedmontmechanical.com/

Russell C. Campbell Engineering Specializing in ventilating, air conditioning, and HVAC. http://www.rccengineering.com

TEC, Inc. Providing electrical and mechanical engineering, lighting, plumbing, HVAC, and fire protection systems design. http://www.tecinc1.com/

Trinidad Engineering Provides heating, ventilation, air conditioning and refrigeration (HVAC) engineering and consulting services. http://www.trinidadengineering.com

Weinstein Taylor and Associates Mechanical/electrical engineers, based in Toronto, Canada, specializing in HVAC, life safety, and in the design of energy efficient systems. http://www.wtaeng.com